Basic Concept of Network

ScienceComputer

     Hello, today we will learn about Internet Technology on topic 3.1 Network Basics. Under topic 3.1 Network Basic, there one small topic that we will learn for today which is called 3.1.1 Basic Concept of Network.

     First, we must know the definition of network.

WHAT IS NETWORK?

Based on Shelly Cashman,

Network is a collection of many computers and devices connected together through connections devices and transmission media.

Collection of computers and devices connected together to form a network





Connection between computers and devices in a network can be made through physical wires or cables and wireless (radio waves or infrared signals). 

Did you know what is communications devices?

Well, let me tell you the meaning of communications devices.

Communications devices is any types of hardware that can transfer or transmits data or instructions between sending device and receiving device.




There are 8 types of communication devices:

1)Dial-up Modem

A communications device that can convert digital signals to analog signals and analog signals to digital signals, so that data can travel along an analog telephone line.

2)Wireless Modem

Some mobile users have a wireless modem that uses the cell phone network to connect to the Internet wirelessly from a notebook computer, a smart phone, or other mobile device.

3)Network Card

A communications device that enables a computer or device that does not have built-in networking capability to access a network.

4)Digital Modem (ISDN,DSL, Cable Modem)

A communications device that sends and receives data and information to and from a digital line.

5)Wireless access point

A central communications device that allows computers and devices to transfer data wirelessly among themselves or to transfer data wirelessly to a wired network .

6)Router

A communications device that connects multiple computers or other routers together and transmits data to its correct destination on a network.

7)Switch

A connection device similar to a hub but more sophisticated, including functionality that allows it to control and manage data transmissions.

8)Hub

A connection device that allows multiple connections to the network.

transmission media

meaning:

Materials or substances capable of carrying one or more signals in a communications channel.

Two types of transmission media:

1.Physical transmission media/Guided media/Wired

•Twisted-Pair Cable, Coaxial Cable, Fiber-Optic Cable.

1)Twisted Pair  Cable 
•Twisted-pair cable consists of one or more twisted-pair wires bundled together.
•Widely used transmission media for network cabling and telephone systems.

2)Coaxial Cable

Consists of a single copper  wire surrounded by at
least three layers:

1) An insulating material

2) A woven or braided metal

3) A plastic outer coating .

3)Fiber optic

A transmission media that uses glass or plastic fiber to carry light (laser) signals.

2.Wireless transmission media/Unguided media

•Infrared, Broadcast Radio, Cellular Radio,
Microwave, communications satellite.